John a



(No Model.)

J. A. EVARTS.

FRICTION BRAKE FOR ELEVATING DEVICES.

No. 287,262. Patented 001;. 23, 1883.

n. mumsw Pholo-Lrllmgmplmr. Wmshinglnn. n. c.

UNITED STATES PATENT OFFICE.

JOHN A. EVARTS, OF MEBIDEN, CONNECTICUT, ASSIGNOR TO THE BRADLEY &HUBBARD MANUFACTURING COMPANY, OF SAME PLACE.

FRICTION-BRAKE FOR CELEVATING DEVICES.

SPECIFICATION formingpart of Letters Patent No. 287,262, dated October23, 1883.

7 Application filed September 19,1883. (No model.)

To all whom it may concern.-

Be it known that I, JOHN A. EVARTS, of Meriden, in the county of NewHaven and State of Connecticut, have invented a new Improvement inFrictional Brakes for Liftin g Devices; and I do hereby declare thefollowing, when taken in connection with accompanying drawings and theletters of reference marked thereon, to be a full, clear, and exactdescription of the same, and which said drawings constitute part of thisspecification, and rep resent, in

Figure 1, a side view; Fig. 2, an edge view, looking from the right;Fig. 3, an edge view,

1 5 looking from the left.

This invention relates to an improvement in brakes for lifting devices,with special reference to springs, such as employed for suspending lampsand other articles which are to be held at different elevations, but isapplicable to the wheels of other lifting apparatus, the object being tomake the weight which is suspended serve to apply the brake; and itconsists in a wheel substantially in con- 2 5 nection with thelifting-drum, and a lever having one arm to bear upon said wheel, theother arranged so that the cord or chain by which the weight issuspended will pass over said arm to the drum, and thereby cause the 0weight of the thing suspended to bring one arm of the lever intofrictional bearing upon said wheel, and as more fully hereinafter described.

. In illustrating my invention I show the lift- 3 5 ing device as acommon spring-drum, A. This is arranged in a suitable frame, B, providedwith convenient means, C, for attaching the lifting device at any pointfrom which suspension is desired. One edge of this drum is fitted with awheel or flange, D. In the frame below the axis E of the wheel D a leveris hung upon a pivot or fulcrum, a. One arm, F, of this lever is fittedwith a shoe or surface, I),

Y to bear upon the periphery of the wheel D.

4 5 The other arm, G, extends to the opposite side,

and is there preferably provided with an antifriction roll, (Z. The cordor chain H has one end attached to the drum, and passes from the drumoverthe anti-frictional pulley d,

thence downward. To this chain the thing to be suspended is attached.Suppose, for illustration, the thing sosuspended to be a lamp. Theweight of the lamp is therefore brought directly upon the arm G of thelever, tending to turn that arm downward and the other arm, F, upwardagainst the wheel D, and thereby apply the frictional bearing-surface bof that arm to the periphery of the wheel. This frictional surface underthe weight of the lamp should be sufficient to hold the lamp suspend- 6oed at any desired point of elevation. IVhen it is desired to raise thelamp, simply lift upon the lamp sufficient to relieve the arm G from theentire weight of the lamp, and which will correspondingly reduce thefriction of the other arm upon the wheel D, and permit the spring toreact and wind the cord or chain upon the drum until the lifting-powerapplied to the lamp be removed. Then the weight again falls upon the armG of the lever and applies the brake, as before. The friction of the armF upon the wheel D, as before stated, is only sufficient to hold thelamp at any point of suspension, but is not so great as to resist thepulling down of the lamp, and so that when the lamp is desired at alower elevation pulling downupon the lamp will draw the cord or chainfrom the drum, resisted only by the frictionof the arm F and the powerof the spring, it being understood that in case of such asuspensionspring the power of the spring itself nearly counterbalancesthe weight of the thing suspended. Instead of a springbarrel, it may bea weight applied to a drum, which will counterbalance the fixture orthing 8 5 suspended, substantially as does the spring as beforedescribed.

I represent the lever as applied below; hence a lever of'the first orderis required; but if the' lever be applied, as it may be. above, then thelever will be of the second order.

The uses for such suspending devices are numerous. The illustration asapplied to a lamp will be sufficient for the full understand '9 5 ing ofthe invention.

Vhile I describe the, surface upon which the brake bears as a wheel, D,I do not wish to be understood to mean that such'a wheel independent ofthe drum is necessary, as the,

wheel may be the surface of the drum. Therefore by the term wheel I wishto be understood as-embracing any rotating surface through whichlifting-power is applied.

In case of a broadfaced drum the anti-friction roll (1 should bearranged to slide on its axis from side to side, to lead the chain'orcord from the surface of'the drum. Therefore, as seen in Fig. 8, the armG of the lever is bifurcated, with an arbor across, and the roll (1arranged thereon.

I claim- 1. In a lifting device, the combination of a wheel arranged torevolve and, in connection with the lifting-power, a lever hung to bearupon the periphery of said wheel and JOHN A. EVARTS.

Witnesses:

F. J. SEIDENSTICKER, H. S. SAVAGE.

